Network test systems test data network and storage network equipment by executing tests that measure latency, throughput, roundtrip time, jitter, and other metrics of device performance. All of these tests require precise timing and, in some instances, synchronized timing sources between the test system and the device(s) under test. When the test system is implemented on hardware dedicated to testing and the devices under test include precise timing sources, accurate timing measurements can be obtained from the tests. However, in many instances dedicated testing hardware is not available. For example, when testing data center equipment, physical access to the test environment may be limited. Instead, testing can be performed by loading test software onto data or storage network equipment physical machines. Because the data or storage network physical machines may not have reliable clocks, the test software may not have access to accurate, synchronized clock sources.
The difficulties in executing tests that require precise timing sources is further complicated by the introduction of virtualization in data network and storage network equipment. For example, applications under test in a data network or a storage network may run on top of hypervisor layers which virtualize the underlying physical hardware. In addition, applications under test may be moved among virtual machines after a test is initiated, which may further complicate timing measurements. Similarly, when the test application also runs on top of hypervisor, the test application may not have direct access to the underlying hardware, including clocks, and may also be moved among physical machines. Thus, even if the clock sources on some data network or storage network equipment are accurate, there is no way to guarantee on which physical machine a given application under test or test application will execute. As a result, virtualization increases the difficulty in obtaining accurate timing measurements during equipment testing.
One possible solution to this problem is to connect test equipment and equipment under test with synchronization cables. The clocks on all of the equipment could then be synchronized via signals transmitted over the synchronization cables. However, running synchronization cables throughout a facility is time consuming and may not be possible in the case where the tester does not have physical access to the test facility. Even when the tester has physical access to the facility, running synchronization cables may be difficult, especially when the test system and the system under test are located in different rooms and/or on different floors.
Accordingly, there exists a long felt need for methods, systems, and computer readable media for providing precise timing in a virtual data network or storage network test environment.